When I came home from my Big Wild Sleepout expedition, I found there was something missing.

I felt it intuitively as I approached the front door. Something in the street felt wrong. It wasn’t anything I saw, just the reverse, it was something I didn’t see. Something I didn’t hear.

It took me at least 24 hours to realise that the hole in my life was the absence of swifts. They’d departed for Africa without even leaving a note. Not even a feather. No trace at all.

I was hoping to have an evening where I could sit in the garden, raise a glass and say goodbye to wish them well on their 4,000 plus mile flight to Mpasa in Tanzania or maybe west in Brazzaville on the mighty River Congo.

While I head for the garden to prepare some autumn and winter homes for nature, they’ll be soaring over the jungles and lakes of sub-Saharan Africa, dong their bit to reduce Malaria by gobbling-up mosquitoes and saving crops from other flying buggy pests. Swifts are nature’s pest police. They play an invaluable role in our health and food chains but rarely get any credit.

Another special agent in the UK's secret pest police is the seven spot ladybird. There’s a suggestion from conservation colleagues that this year’s hot and messed up seasons have been bad news for seven spots. That’s very bad news for all of us. Without the right investment, our pest police are undermined, leaving our food crops vulnerable to unchecked infestations and giving disease carrying bugs free rein.

So while the swifts are away, it’s an ideal time to build new nesting opportunities for them in new buildings or to add nest boxes to older ones. Now’s a great time to build water features and acclimatise new plants into pots so they’ll be established come the dormant winter months. Effort now will have a huge impact on how we experience next spring and summer.

When I first heard about the Big Wild Sleepout I was determined to pitch a tent in central London. All enquiries led pretty much to the same response: “you can’t camp here. Local by-laws prohibit camping here!”

As it happened, the Sleepout weekend clashed with a rare opportunity to visit relatives in America, so camping plans were revised. I wanted to make it an occasion my children would remember, so booked a pitch in Yellowstone National Park.

All the blurb said it was hot by day and cold at night, it being some 7,000 plus feet above sea level. No problem.

On arrival in the States, we borrowed a couple of small tents and sleeping bags and were ready for the fun to begin. All my sanity and wits vanished as Gogol Bordello’s Eugene Hütz sang.

The campsite was deep in a forest. It was clean and well equipped with great showers and generous supplies of hot coffee. On the downside, you weren’t allowed any food or drink, not even water, in your tent in case it attracted bears.

One of the many guide books we read comfortingly suggested that in the event a bear did come snuffling round your tent, simply scare them off by making some noise, perhaps loudly singing a tune from one of the big musicals such as Mary Poppins. Comforting advice I thought.

They’d said it got cold, but after the first night, as my partner and I shivered bleary eyed from our tent in thin clothes as the sun rose, we noticed other campers wore wooly hats, thermal clothes, gloves and puffer jackets. It was at this point that I regretted an assertion than towels would be ample for sleeping on.

The second night, we wore almost all of our clothes. The ground was no softer and come 4 am I heard a strange noise outside the tent. At first I couldn’t make it out, then clarity hit. Someone with the same guidebook as us had been spooked and was trying valiantly to hum ‘Feed the Birds’. It was such a feeble attempt I felt safe in the knowledge that if there was a bear, the humming camper would be first on its menu.

It was a memorable camping experience. We did see amazing things. None of us will ever forget it and we have vowed to go camping again; this time with sleeping mats, arctic tog sleeping bags and simple comforts such as lights, cooking stuff and pillows, definitely pillows.